GstTypeFind

typedef struct {
  /* private to the caller of the typefind function */
  guint8 *  (* peek)       (gpointer         data,
                            gint64           offset,
                            guint            size);

  void      (* suggest)    (gpointer         data,
                            guint            probability,
                            const GstCaps *  caps);

  gpointer     data;

  /* optional */
  guint64   (* get_length) (gpointer data);
} GstTypeFind;

Object that stores typefind callbacks. To use with GstTypeFindFactory.

GstTypeFindFunction ()

void                (*GstTypeFindFunction)              (GstTypeFind *find,
                                                         gpointer data);

A function that will be called by typefinding.

enum GstTypeFindProbability

typedef enum {
  GST_TYPE_FIND_MINIMUM = 1,
  GST_TYPE_FIND_POSSIBLE = 50,
  GST_TYPE_FIND_LIKELY = 80,
  GST_TYPE_FIND_NEARLY_CERTAIN = 99,
  GST_TYPE_FIND_MAXIMUM = 100
} GstTypeFindProbability;

The probability of the typefind function. Higher values have more certainty in doing a reliable typefind.

gst_type_find_peek ()

guint8*             gst_type_find_peek                  (GstTypeFind *find,
                                                         gint64 offset,
                                                         guint size);

Returns the size bytes of the stream to identify beginning at offset. If offset is a positive number, the offset is relative to the beginning of the stream, if offset is a negative number the offset is relative to the end of the stream. The returned memory is valid until the typefinding function returns and must not be freed.

gst_type_find_suggest ()

void                gst_type_find_suggest               (GstTypeFind *find,
                                                         guint probability,
                                                         const GstCaps *caps);

If a GstTypeFindFunction calls this function it suggests the caps with the given probability. A GstTypeFindFunction may supply different suggestions in one call. It is up to the caller of the GstTypeFindFunction to interpret these values.

gst_type_find_suggest_simple ()

void                gst_type_find_suggest_simple        (GstTypeFind *find,
                                                         guint probability,
                                                         const char *media_type,
                                                         const char *fieldname,
                                                         ...);

If a GstTypeFindFunction calls this function it suggests the caps with the given probability. A GstTypeFindFunction may supply different suggestions in one call. It is up to the caller of the GstTypeFindFunction to interpret these values.

This function is similar to gst_type_find_suggest(), only that instead of passing a GstCaps argument you can create the caps on the fly in the same way as you can with gst_caps_new_simple().

Make sure you terminate the list of arguments with a NULL argument and that the values passed have the correct type (in terms of width in bytes when passed to the vararg function - this applies particularly to gdouble and guint64 arguments).

Since 0.10.20

gst_type_find_get_length ()

guint64             gst_type_find_get_length            (GstTypeFind *find);

Get the length of the data stream.

gst_type_find_register ()

gboolean            gst_type_find_register              (GstPlugin *plugin,
                                                         const gchar *name,
                                                         guint rank,
                                                         GstTypeFindFunction func,
                                                         gchar **extensions,
                                                         const GstCaps *possible_caps,
                                                         gpointer data,
                                                         GDestroyNotify data_notify);

Registers a new typefind function to be used for typefinding. After registering this function will be available for typefinding. This function is typically called during an element's plugin initialization.